The field of the invention is marker compositions for fluids. More particularly, the invention relates to multi-layered marker compositions.
A marker is a substance which can be used to tag products, typically petroleum products, as well as alcohols and a number of other suitable fluids, for subsequent detection. The marker is normally dissolved in a fluid to be identified, then subsequently detected by performing a physical or chemical test on the tagged fluid. For example, markers are sometimes used by government authorities to ensure that the appropriate tax has been paid on particular grades of fuel. Oil companies also mark their products to help identify those who have diluted or altered their products. These companies often go to great expense to make sure their branded petroleum products meet certain specifications regarding volatility and octane number, for example, as well as to provide their petroleum products with effective additive packages containing detergents and other components. Consumers rely upon the product names and quality designations to assure that the product being purchased is the quality desired.
It is possible for unscrupulous persons to increase profits by selling an inferior product at the price consumers are willing to pay for a high quality branded or designated product. Higher profits can also be made simply by diluting the branded product with an inferior product. Policing retailers/dealers, for example, who substitute one product for another or blend branded products with inferior products is difficult in the case of gasoline because the blended products will qualitatively display the presence of each component in the branded products. The key ingredients of the branded products are generally present in such low levels that quantitative analysis to detect dilution with an inferior product is very difficult, time consuming and expensive.
Marker systems for petroleum products, including, but not limited to, fuels, lubes, greases, etc., have been suggested but various drawbacks have existed which have hindered their effectiveness. Many currently available markers cannot be used as both forensic markers, detected by, but not limited to analysis by Gas Chromatography (GC), and simple field test markers detected by, but not limited to, development or extraction of the marker. Many known markers are easily removed from the fluid to which they are added destroying the integrity of the marker system. Many currently available markers cannot be easily combined to detect marker product with a component that cannot be laundered from the fuel. And current methods of lab analysis of these markers ends to be very expensive.
In view of the above, it would be desirable to provide a composition useful as a marker and that could be detected not only in the field, but also in the lab. It would be desirable to combine field test technology with existing chromatography techniques to provide not only field test results but also a laboratory confirmation of the marker presence, using common lab techniques, such as, but not limited to, analysis by GC. Additionally, the marker should be able to accomplish the above and remain resistant to undesired extraction or removal (laundering) by unscrupulous persons. Additionally it would be desirable to provide a marker composition that could be used in a wide variety of fluids, including, but not limited to, petroleum products, alcohols, etc. Petroleum products may include, but are not limited to, fuels, lubes, greases, etc. It would also be desirable to provide economical detection methods not requiring advanced training of the operator.